TiO2 Nanotubes Array Based Ti/TiO2NTs/SnO2-Sb-Bi/NATO Electrode for Electrosynthesis of Ozone Water and Application in Wastewater Treatment

Ozone water is widely used in disinfection area and wastewater treatment due to its strong oxidation. Recent studies have found that Ti/SnO 2 -Sb-Ni (NATO) anode has higher O 3 generation efficiency due to its higher oxygen evolution potential. In this paper, TiO 2 nanotubes (TiO 2 -NTs) were prepared by anodic oxidation method as the basic substrate material for the Ti/SnO 2 -Sb-Ni electrode, and SnO 2 -Sb-Bi was introduced as the intermediate layer to investigate the electro-synthesis of ozonated water. Studies show that the modification of the TiO 2 -NTs substrate provides a larger specific surface area for the reaction and accelerates the transfer of electrons from the oxide layer to the substrate. The introduction of the SnO 2 -Sb-Bi intermediate layer effectively delays the electrode deactivation and also enhances the electron transport. When the Ti/TiO 2 NTs/SnO 2 -Sb-Bi/NATO electrode was used and electrolyzed for 15 min, the ozone water concentration reached 13.15 mg L −1 , about twice as much as the unmodified electrode. The effects of current density and the coating numbers of active layers on the electrosynthesis of the ozonated water were also investigated. Finally, the application of ozonated water in the decolorization of organic dye wastewater was investigated based on its strong oxidation property, the degradation rate of 40 ppm methylene blue reached 94.5 % and the COD removal rate reached 72.9 % in 30 min. In addition, the cell voltage remained constant during decoloration, indicating the good stability of the electrode. This study also opens a door to the rapid electrochemically decoloration of wastewater and sterilization area by using electrochemically obtainable ozone water.